A navigation system for use in a vehicle conventionally determines a current position of the vehicle based on an autonomous navigation method and a radio navigation method. The autonomous navigation method determines the current position of the vehicle by employing measurement of geomagnetism, direction and/or vehicle speed as well as map data. That is, an estimated position of the vehicle based on the measurement is adjusted and “matched” with, for example, a position of a road to be suitably displayed on a map in a display unit of the navigation system. This process is called as “Map matching.” The radio navigation method determines the current position of the vehicle by employing radio signals received from plural satellites for map matching. Some of the currently available navigation systems use both of the autonomous navigation method and the radio navigation method for accurately determining the current position of the vehicle.
The navigation system in a disclosure of the Japanese Patent Document JP-A-2003-227725 uses a camera disposed on a vehicle for capturing image of a road and precisely determining a type of the road, that is, a local road, an expressway or the like.
However, the navigation system of the above-described type is not capable of determining a traveling condition of the vehicle at a specific moment such as going into an intersection, going into a parking lot by leaving a local road or the like.